Oil burner



y 1941- c. T. ASBURY 2,249,878

011. BURNER Filed Jan. 21, 1939 *2 Sheets-Sheet l UIJU [HUI July 22,1941. c. T. ASBURY OIL BURNER Filed Jan. 21, 1939 2 Sheets-Sheet 2Patented July 22, 1941 UNITED STATES PATENT OFFICE OIL BURNER Charles T.Asbury, Elklns Park, Pa. Application January 21, 1939, Serial No.252,202

6 Claims.

This invention relates to new and useful improvements in oil burners andmore particularly to oil burners of the rotary head wall-flame type.

As is well known, fuel oils for domestic oil burner firing arenumerically graded in relation to their volatility, viscosity,flash-point, etc. according to standards determined by the NationalBureau of Standards, and current standards for such oils are set forthin a pamphlet entitled "Commercial Standard 0512-38. These fuel oils,beginning with No. 1, which is a relatively volatile high grade oil, areof decreasingly lower grade to No; 6 which is of relatively highviscosity.

It is well known in both the fuel oil and oil burner industries thatdomestic oil burners of the rotary head wall-flame type as nowconstructed, for the most part, require the use of a moderately volatilefuel oil such as No. 2 to the exclusion of the use of lower grade lowviscosity fuel oils such as No. 3 which, in addition to having a higherB. t. u. rating, usually is less expensive than No. 2 oil.

After many months work on'the problem, I have found that this conditionapparently results from the fact that in the rotary head type oilburners now on the market the fuel oil is discharged from thedistributor or head in the form of more or less compact jets or streams,while air for mixture with the fuel to insure combustion thereof isdischarged by the head from below the point of discharge of the oil.

With the foregoing observations in mind, the present invention consistsessentially in the discovery that by causing the relatively compactstreams of fuel oil to be distributed over a relatively large area inthe form of a thin film prior to being discharged radially from thehead, and at the same time causing the air for combustion to bedischarged from above the point of discharge of the fuel oil, so that itcontacts and mixes with the oil in a region radially remote from thehead, I am able to burn lower grade fuel oils of higher B. t. u. ratingthan has heretofore been possible in burners of the type mentioned.

These results apparently are due to two fac-- tors. In the first place,since the oil is spread out over a relatively large area prior todischarge, in contrast to the relatively dense compact streamsheretofore used, instantaneous ignition of lower grade more viscousfuels may be effected and, secondly, by discharging the air from thehead abovethe point of discharge of the fuel, the air tends to mix withthe fuel at a distance relatively remote from the head, rather thansubstantially at the point of discharge of the fuel as occurs when theair is discharged at or below the level of fuel discharge, and any tenofoil burner wherein the fuel oil is discharged radially from the head inthe form of a relatively thin film or sheet and the air for combustionthereof is discharged by said head from above the point of discharge ofthe fuel so as to mix with the latter in a region relatively remote fromthe head.

The invention also consists in certain novel features and details ofconstruction and arrangement hereinafter fully set forth and shown inthe accompanying drawings, in which:

Figure 1 is a fragmentary view in section vertically through a rotaryhead type oil burner embodying the present invention.

Figure 2 is a detached view in perspective partly in section of the headportion of the burner illustrating certain details of the constructionthereof.

Figure 3 is a view similar to Figure 1 illustrating a modified form ofthe invention;

Figure 4 is a top plan view of the modification shown in Figure 3; and

Figure 5 is a fragmentary view in section showing a modified arrangementof heat shield for the fan and baflle construction shown in Figure 1.

Referring now more particular to Figures 1 and 2 of the drawings,reference numeral l designates the main supporting frame of the burnerwhich comprises an annular wall member 2 provided with'lugs 241 for thereception of threaded leg members 3 which extend into supportingcylinders 4 provided with suitable base members 5. Mounted on eachthreaded member 3 is a lock nut 6 that rests on top of the cylinders 4so that the frame I can be leveled, raised and lowered to a desiredposition and locked in place. The annular wall member 2 is furtherprovided with an annular lip I to receive the edges of the plates 8which support the refractory hearth tile or brick 9.

A motor I0 is suitably secured centrally with respect to the frame I andarranged with its shaft ll extending axially upward through the annularwall member 2 thereof, the lower end of the shaft ll of the motor Itbeing journaled and supported in a ball race or bearing l2.

An oil distributor head designated generally as l3 having relativelylarge air openings Ila is mounted upon the upper end of the motor shaft"by means of a central boss I, and an oil supply pipe l5 provided withan outwardly re-bent tip it is supported from and extends upwardlyadjacent the motor Ill so that said tip it overhangs a channel memberll. The

channel member I1 is provided with an upwardly and outwardly slopingouter wall it and this terminates in a horizontal flange i8 whose outeredge portion 23 is re-bent around a flange 2! at the periphery of thedistributor head i3. Extending diagonally upward and outward from thedistributor head |3 are one or more radial oil distributor passages 22and the inner ends of these communicate with the underside of said headl3 at the upper inner edge surface of the channel outer wall II.

A feature of the invention resides in the novel construction andarrangement of a combination fan and battle member designated generallyby reference numeral 23 and mounted upon the motor shaft II, above thehead, for rotation therewith. The said fan and baille member 23 aresuitably spaced above the distributor head l3 by means of a sleeve 24and said fan and bailie member and the distributor head |3 are securedtightly upon the shaft II for rotation therewith by means of a nut orthe like 25. As shown in Figures 1 and 2 of the drawings the fan andbaiiie member 23 is of generally inverted dish shape having animperforate top or cover section 26 and depending peripheral wallportion 21 provided with a series of openings 23 and blades 29constituting a fan or blower. Ad- .iacent the lower end of saidperipheral portion 21 the said wall extends downwardly at an obtuseangle with respect to said portion 21 as indicated at 3| to form a lowerimperforate bailie or ring portion spaced outwardly adjacent the outletends of the oil distributor passages 22. It is also contemplated toprovide the member 23 with a heat shield 32 arranged outwardly ad-Jacent the baille 3| for the p p se of maintaining the latter relativelycool and thereby minimizing the formation of carbon on said bailie.

Thus the fan which provides air for combustion of the oil fuel isdisposed above the points.

of oil discharge and in operation of the device, as the head I! andchannel member I! rotate together with the fan and baffle member 23, theoil, fed to said channel member II by the pipe l5, works its wayupwardly along the wall I! thereof and into the passages 22 through andby means of which said oil is flung radially against the inner surfaceof said bailie portion 3| of the member 23. As the oil impinges againstthe baflle 3| the obstruction afforded by the latter causes said oil tospread or thin out over a relatively large area in the form of a filmwhich flows downwardly along the inner wall of said bailie 3| to thelower edge thereof from which it is flung radially outward to a pointadjacent the wall of the furnace.

As the oil fuel is thus thinned out and disblades 29 in the upperportion 21 of the member 23 function as a fan or blower to draw airupwardly through the opening in the hearth provided by the annular frame2 and thence upwardly between the channel l1 and shaft H and openings|3a in the head I 3 as well as upwardly through the space between saidhead l3 and baflie 3| after which it is discharged outwardly through theopenings 23 and radially from the member 23 for mixture with theunderfed fuel at a point radially remote from the burner structure.

The variousdetails of construction of the fan and battle member justdescribed may of course be varied so long as the previously mentionedessential features are retained, and a modified form thereof which givessatisfactory results is v charged from the lower end of the baflie, theI shown in Figures 3 and 4 of thedrawings. In

- this form the i'an and baflle member is designated 83 and generallyspeaking is of annular or ring form having an inner wall portion 34providing a baflie spaced outwardly adjacent the oil discharge passages22 and an outer wall portion 35 providing a heat shield intermediate thebaffle 34 and which functions in a manner similar to the shield 32 tomaintain said baflle 3d substantially cool thus minimizing carbonforming on the battle.

The baffle ring is mounted upon the motor shaft II .by means of a spiderstructure 33 located within the annular baiiie and provided with acentral boss 31 for reception of said shaft, a nut 38 being employed tosecure the said fan and baflle member 33 on the shaft H for rotationtherewith. A unique feature of this particular form of the device is thefact that the spokes or elements of the baiiie supporting spiderstructure 3B are of radially increasing width and provided with adefinite curvature declining in the direction of their leading edge toconstitute fan blades. The blades thus provided by the spokes of thespider 36 function, after the manner of the blades 29 previouslydescribed, to draw air upwardly through the hearth opening and thenceupwardly between the channel I1 and shaft II and openings |3a in thehead l3 as well asupwardly through the space between the latter and thebaiiie 34 after which it discharges and mushrooms outwardly anddownwardly for mixture with the underfed fuel at a point radially remotefrom the burner structure, the oil being discharged from the lower edgeof said baiiie 34 in the form of a thin film after discharge from thepassages 22 against the inner surface of the baflle in the mannerpreviously described.

A modified form of heat shield for the fan and baiile member 23 shown inFigures 1 and 2 is shown in Figure 5 of the drawings. In thisarrangement the heat shield 32a forms an integral part of the member 23and is formed by upwardly turning the lower edge of the portion 3|constituting the baffle. This particular arrangement of the heat shieldprovides an upwardly opening channel 39 which, during rotation of theburner head, catches a portion of the air discharged by the blades 29 ofthe fan which aids in maintaining the baiiie portion 3| relatively cool.

In the two forms of rotary head burners illustrated and described hereinit will be observed that substantially all of the air drawn through thehearth opening defined by the annular wall member 2 is caused to bedischarged from a point above that of the fuel discharge, thuspreventing mixture of the air and fuel at a point adjacent the peripheryof the head as is the case when the air is discharged at or below thelevel'or point of fuel discharge, and insuring such fuel and air mixturetaking place in a region radially remote from said head. Thisarrangement together with that of impinging the streams of oil against abaflie to disperse them over a large area in the form of a film prior todischarge for combustion enables the efficient burning of lower gradefuel oils of higher B. t. u. rating than heretofore possible thusaffording a greater heat output per unit quantity of fuel at generallydecreased cost.

While certain particular embodiments of the invention have beenillustrated and described herein, it is not intended that the inventionbe precisely limited thereto but that changes and modifications may beincorporated and embodied therein within the scope of the annexedclaims.

In this connection, it is pointed out that successful operation of thedevice is not confined to battle structures which rotate with the fueldistributor head but that equally successful results are obtained withthe use of a stationary bafile and the limitation of the disclosureherein to devices embodying rotating baflles is solely because sucharrangements are deemed the more practical from the standpoint ofsimplicity and cost of manufacture.

I claim:

1. In a burner structure of the type described, the combination with ahead rotatable about a vertical axis and having means for laterallydischarging streams of liquid fuel, of a structure mounted above saidhead and rotatable therewith comprising a depending baille disposed inthe path of said streams of liquid fuel and against which said streamsimpinge and disperse in the form of a thin film prior to dischargeradially outward therefrom, means disposed at a level above saidrotatable fuel stream discharging head for entraining air anddischarging the same from above the fuel discharge for admixture withsaid fuel in a region radially remote from the rotatable head to form acombustible mixture, and means disposed outwardly adjacent said bafileconstituting a shield for the baffle against the heat of combustion ofsaid mixture.

2. In a burner structure of the type described, a head rotatable about avertical axis constructed and arranged for laterally discharging streamsof liquid fuel comprising an annular fuel receiving channel member and ahead element superimposed thereon provided with at least one laterallydirected fuel discharge passage and an upwardly directed air opening,and a structure mounted above said head and rotatable therewithcomprising a depending bafile disposed laterally adjacent the outlet endof said fuel discharge passage and against which fuel discharged fromsaid passage impinges and is dispersed in the form of a thin film priorto discharge radially therefrom, and means disposed at a level abovesaid bafile and fuel discharge head for entraining air upwardly throughthe discharge head and its air opening and between said fuel dischargehead and the baffle and discharging the same from above the fueldischarge region for admixture with said fuel in a region radiallyremote from the head to form a combustible mixture.

3. In a burner structure of the type described, a head rotatable about avertical axis constructed and arranged for laterally discharging streamsof liquid fuel comprising an annular fuel receivin channel member and ahead element superimposed thereon provided with laterally directed fueldischarge passages and upwardly directed air openings, and a structuremounted above said head and rotatable therewith comprising a dependingbaffle disposed laterally adjacent the outlet ends of said fueldischarge passages and against which the streams of fuel discharged fromsaid passages impinge and disperse in the form of a thin film prior todischarge radially therefrom, means disposed at a level above saidbaffle and fuel discharge head for entraining air upwardly through thedischarge head and its air openings and between said fuel discharge headand the bafiie and discharging the same from above the fuel dischargeregion for admixture with said fuel in a region radially remote from thehead to form a combustiblemixture, and means disposed outwardly adjacentsaid bailie constituting a shield for the battle against the heat ofcombustion of said mixture.

4. In a burner structure of the type described, a head rotatable about avertical axis constructed and arranged for laterally discharging streamsof liquid fuel comprising an annular fuel receiving channel member and ahead element superimposed thereon provided with laterally directed fueldischarge passages and a plurality of upwardly directed air openings; abaffle disposed laterally adjacent the outlet ends of said fueldischarge passages and against which the streams of fuel discharged fromsaid passages impinge and disperse in the form of a thin film prior todischarge radially there from, and draft inducing means disposed at alevel above said fuel discharge head and rotatable therewith forentraining air upwardly through the discharge head and its air openingsand between said fuel discharge head and the baflle and discharging thesame from above the fuel discharge region for admixture with said fuelin a region radially remote from the head to form a combustible mixture.

5. In a burner structure of the type described, a head rotatable about avertical axis constructed and arranged for laterally discharging streamsof liquid fuel comprising an annular fuel receiving channel member and ahead element superimposed thereon provided with laterally directed fueldischarge passages and a plurality of upwardly directed air openings, abaiile disposed laterally adjacent the outlet ends of said fueldischarge passages and against which the streams of fuel discharged fromsaid passages impinge and disperse in the form of a thin film prior todischarge radially therefrom, means disposed at a level above said fueldischarge head and rotatable therewith for entralning air upwardlythrough the discharge head and its air openings and between said fueldischarge head and the baffle and discharging the same from above thefuel discharge region for admixture with said fuel in a region radiallyremote from the head to form a combustible mixture, and means disposedoutwardly adjacent said baiile constituting a shield for the baffleagainst the heat of combustion of said mixture.

6. In a liquid fuel burner structure of the type described, a headrotatable about a vertical axis and having at least one opening thereinfor laterally discharging a stream of liquid fuel, depending bafilemeans rotatable with said head and disposed in the path of discharge ofthe fuel stream for engagement by said stream and operable to dispersethe same into a relatively thin film and then discharge the sameradially outward from the lower edge of said baffle means, and meansalso rotatable with said head for discharging air laterally outward fromthe burner structure for admixture with said discharged fuel, the pointof air discharge from the burner structure being at a level above thepoint of fuel discharge from the baffle and the spacing of said level ofair discharge above said point of fuel discharge being such that mixtureand combustion of said discharged air and fuel takes place only in aregion radially remote from the point of fuel discharge from said bafliemeans.

' CHARLES T. ASBURY.

